500 efi surging at 3000 rpms
 

thanks

Question After you cleared the code Did it come back on it's own with out you unpluging the wires??? Also if your MAP sensor has A rubber o ring or seal/grommet of any kind at the end of it make 100% sure it is not damaged in anyway or the engine could run like this. Open this link up and then open number nine and check out the little grommet in this link.

http://www.mercruiserparts.com/Show_...rs+And+Sensors

What year is the engine?

Engine is a 1999. cleared codes and runs ok